option('gtk_doc',
       type: 'boolean', value: false,
       description: 'Whether to generate the API reference')
option('doc',
       type: 'feature', deprecated: {'true': 'enabled', 'false': 'disabled'},
       description: 'Whether to generate the doc')
option('tests',
       type: 'boolean', value: false,
       description: 'Whether to compile unit tests')
